Injection processes of parts or sets of parts requiring simultaneous or sequential injection of more than one material or details, which despite being of the same material, cannot be executed by the injection assembly of the base machine, involve the need for additional injection.
These processes known in the art involve the use of other additional injection systems, in addition to the injection assembly of the base injection machine. Mounting and connecting these additional injection assemblies involve several installation problems, often requiring significant additional space around the main machine.
Another significant limitation of additional injection systems known in the art relates to security issues. Installation and connection thereof to mold inlets often come into conflict with construction details of the base injection machine, particularly with doors and protective shields, thus becoming necessary to both remove security items originally installed in the machine and install additional shields around the systems.
Other types of limitations relate to mechanical stability of assemblies on machinery and molds that give rise to the need for making and using special supporting structures, resulting in significant room problems.
Another limitation is that current additional injection systems also greatly interfere with automation/robot control requirements necessary to the extraction or mounting of parts produced by the mold, due to the room they take up outside the injection machine and mold. When the base machine is used in a flexible manner to produce other parts which do not require additional injection or which involve other additional injections, dismounting these components is always a time consuming and often complex operation and its volumetric hampers handling and subsequent storage thereof.
Moreover, mounting additional peripheral injection groups usually involves long distance flow channels, with the inherent energy and rheological inconveniences.
Finally, another limitation often found is that considerable amounts of melted raw material are lost in the abutment regions between the nozzle of the additional injection unit and the mold, during the injection process with the abutment and retraction of the nozzle, which causes the melted raw material to accumulate in areas that eventually compromise a proper operation of the mold.
In a conventional system, each complementary injection equipment assembly would be installed outside the machine with connections to the mold from the outside thereof, in a position dependent on the inlets defined for additional injection, on many ways associated with size of complementary units, on construction details of the molds and on the primary injection machine itself, as illustrated in sections A), B), C) or D) in FIG. 18, as an independent unit attached to the mold from the outside. One solution would be integrating components which enable the process of complementary or additional injection into the mold itself, which requires that the design, constitution and construction thereof be limited by room reservation on the inside in order to accommodate said components, which tend to be exclusively dedicated to a single mold, meaning that the flexibility in the use thereof for other injection processes is lost.